Sensitive electronic components must remain within a certain temperature to operate properly. This becomes an engineering challenge when the sensitive electronic components operate in at least one of extreme temperature conditions and high power (and high component density) electronic packaging configurations. A typical example is an inertial guidance system used for oil wellbore exploration (where drilling depths achieve over 12,000 meters). Since the average temperature of the Earth ranges from 15 to 35° C. per kilometer beneath the Earth's surface, the electronic components need to withstand temperatures ranging from 180 to 420° C.
Conventional cooling techniques (such as forced convection cooling) are not suitable in these types of operating environments. Alternatives include cooling only certain (that is, critical) sensitive components susceptible to high temperatures rather than an entire electronic circuit board or assembly. In addition, controlling mechanisms may be necessary to operate a particular cooling system once the temperature of the sensitive electronic components approaches a critical level (threshold).